All U.S. patent cited herein are hereby fully incorporated by reference.
Floor mats have long been utilized to facilitate the cleaning of the bottoms of people's shoes, particularly in areas of high pedestrian traffic such as doorways. Moisture, dirt, and debris from out of doors easily adhere to such footwear, particularly in inclement weather and particularly in areas of grass or mud or the like. Such unwanted and potentially floor staining or dirtying articles need to be removed from a person's footwear prior to entry indoors. As will be appreciated, such outdoor mats by their nature must undergo frequent repeated washings and dryings so as to remove the dirt and debris deposited thereon during use. These mats are generally rented from service entities which retrieve the soiled mats from the user and provide clean replacement mats on a frequent basis. The soiled mats are thereafter cleaned and dried in an industrial laundering process (such as within rotary washing and drying machines, for example) and then sent to another user in replacement of newly soiled mats. Furthermore, it is generally necessary from a health standpoint to produce floor coverings on which persons may stand for appreciable amounts of time which will provide comfort to such persons to substantially lower the potential for fatigue of such persons by reducing the stress on feet and lei joints through cushioning.
Typical carpeted dust control mats comprise solid and/or foam rubber backing sheets which must be cleated in some manner to prevent slippage of the mat from its designated area. Such cleats are formed during a vulcanization step and have required a time-consuming procedure of placing the green (unvulcanized) rubber sheet on a molded, perforated silicone pad which is itself placed by hand on the conveyor belt of a dust control manufacturing apparatus. The finished mat is then removed after vulcanization from the non-stick silicon pad. The resultant mat product possesses cleats formed through the melting and forcing of part of the rubber backing through the pad perforations during vulcanization. Such cleats provide anti-slip or anti-creep characteristics to the finished mat when placed upon a surface to be protected. Various types, shapes, and arrangements of cleats have been utilized in the past for such anti-creep benefits with dust control mats. Examples include U.S. Pat. Nos. 4,741,065 to Parkins, 5,170,526 to Murray, and 5,227,214 to Kerr et al.
As noted above, previous methods of providing such cleat features to rubber-backed mats are generally produced through the utilization of a perforated silicon pad which is placed by hand on a conveyor belt on in in-line vulcanization apparatus. A rubber article is then placed on top of silicon pad, and optionally a fabric pile (such as a carpet) is then placed, again by hand, on top the rubber article. The conveyor belt then transports the entire composite to a vulcanization chamber wherein it is pressed at a pressure of from about 25 to about 40 psi at a temperature of from about 300 to about 400.degree. F. for anywhere between about 30 seconds and 20 minutes. After vulcanization, the conveyor belt transports the finished composite (floor mat plus silicon pad) out of the chamber. The floor mat is then removed from the pad and allowed to cool and the pad is moved, by hand, back to a location on the conveyor belt, prior to the chamber, in order for another rubber article to be placed thereon. Such a procedure is labor-intensive and inefficient. However, until now, there have been no disclosures of proper methods to reduce the time and labor required to effectively and efficiently produce rubber-backed cleated floor mats. There have been developments in conveyor belts, particularly those covered with Teflon.RTM. coatings, for utilization in other rubber molding processes. However, there has been no discussion or suggestion regarding the problems associated with cleat-forming perforated conveyor belts in the past. In light of the above, it will be appreciated that there is a need for a process and apparatus to efficiently produce cleats within the rubber backing of an anti-creep floor mat. The present invention thus represents a useful advancement over prior practice.